I should probably mention that I'll be coming with my wife and 2 kids (age 3 & 11)

The ones in Cambridge and Woburn have indoor pools too so that's a plus for the kids.

Between Cambridge & Woburn what's the better area / hotel?

Google Maps says that the one in Cambridge is about 5 Miles / 20 Minutes from the Garden and the one in Woburn is about 10 Miles / 15 minutes. (Not sure how the one that is 10 Miles away is a shorter drive?)